The present invention relates to bale handling apparatus which are mounted on farm vehicles such as tractors or the like and which are used for gripping large bales of cut crop material and for transporting, lifting, stacking and unrolling of such bales.
Several prior art bale handling machines have previously been developed for conveying and lifting large bales of hay and the like. See, for example, U.S. Pat. Nos. 3,880,305 to Van Polen, issued Apr. 29, 1975 and 3,908,846 to Brummit, issued Sept. 30, 1975. None of the prior art machines, however, have presented a completely satisfactory means for handling bales which provides both adequate control over the bale as well as facilitates sufficient vertical movement of the bale. As shown in the patents cited above, the bale handling machines commonly employed include a pair of arms which are engagable against opposite sides of a bale in order to grip the bale for conveying and lifting. One drawback inherent in such prior art apparatus is that the gripping arm assemblies do not sufficiently restrict parallel movement of the arms. When, for example, the tractor and baling machine are used on a hillside, due to the substantial weight of the bales, the bale and the gripping arms tend to swing laterally with respect to the axis of the tractor. A further disadvantage of such prior art machines is that the means employed for supporting the gripping arms does not provide a satisfactory range of vertical movement of the bale.